The tropomyosin receptor kinase (Trk) is a family of receptor tyrosine kinases and has a function as a receptor of neurotrophin (NT). Three maj or subtypes of Trk receptors are TrkA high-affinity receptor for nerve growth factor (NGF), TrkB high-affinity receptor for brain-derived neutrophic factor (BDNF) and NT-4/5, and TrkC high-affinity receptor for NT-3. All receptors involve in various physiological function in vivo. TrkA is mainly expressed in peripheral and central nerves, and involves in neuronal development and differentiation, and maintenance of neuronal functions. The gene mutation in TrkA is associated with painless anhidrosis in human (Patent Documents 1, 2 and Non-patent Documents 1 to 3). The activation of NGF-TrkA signal produces hypralgesia (Non-patent Documents 4 to 6). Clinical and non-clinical researches regarding anti-NGF antibodies and non-clinical researches regarding Trk inhibitors reveal the involvement of NGF-TrkA signal or NT-Trk signal in the pain of osteoarthritis, rheumatoid arthritis, bone fracture, interstitial cystitis, chronic pancreatitis and prostatitis in addition to nociceptive pain such as chronic low back pain, neuropathic pain such as diabetic peripheral neuropathic pain, acute pain such as postoperative pain and chronic pain such as pelvic pain and cancer pain (Patent Documents 1, 2 and Non-patent documents 7, 8).
Trk receptors are also expressed in several types of cancer cells such as neuroblastoma, prostate cancer, lung cancer, breast cancer, gastric cancer and pancreatic cancer, and involve in the proliferation and migration of cancer cells. The fusion protein combined with TrkA kinase domain causes the proliferation of lung cancer cells. Trk inhibitor is shown to suppress the proliferation and metastasis of cancer cells in animal model. (Patent Document 1 and Non-patent Documents 9 to 12). Furthermore, Trk receptors are expressed in mast cells, eosinophils, immunocompetent cells such as T and B cells and keratinocytes, and NGF-trkA signal or NT-Trk signal involves in inflammatory bowel diseases such as ulcerative colitis and Crohn's disease, allergic diseases such as asthma and rhinitis, and skin diseases such as psoriasis, atopic dermatitis and pruritus (Patent Documents 1, 2). In addition, the inhibition of NGF-TrkA signal improves the overactive bladder (Patent Document 1). NT-Trk signal also involves in Sjogren's syndrome (Patent Document 1) and endometriosis (Patent Document 1). TrkA receptor plays a critical role in the infection process of the parasitic infection of Trypanosoma cruzi (Chagas disease) (Patent Document 1). Therefore, the compounds having an inhibitory activity for TrkA will be effective for various diseases including nociceptive pain, neuropathic pain, cancer, inflammatory diseases, allergic diseases and dermatological diseases.
The compounds that have an inhibitory activity for TrkA are disclosed in Patent Documents 1 to 15 and Non-patent Documents 6, 13 to 14. However, the compounds related to the present invention aren't indicated and suggested in any documents.
Cyclohexane compounds that produce analgesic effect are disclosed in Patent Documents 16 to 19 and Non-patent Documents 15 to 16, but these compounds don't show an inhibitory activity for TrkA.